Automatic firearm



April 1931- K. HEINEMANN 1,802,422

AUTOMATI C FIREARM Filed July 22, 1930 QUIN AT'I'U RN BK Patented Apr. 28, 1931 UNITED STATES GERMANY, ASSIGNOR TO RHEINISCI-IE METALL- KARL HEINEMANN, 0F DUSSELDORF,

P TENT orr clz AUTOMATIC FIREARM Application filed July 22, 1930, Serial No. 469,795, and in Germany m 29, 1929.

My invention relates to a device for changing or altering the firing speed of automatic fire arms having a toggle-joint breech in which the closing spring acts, by means of a pressure slide, in a well known manner, upon a locking lever of the toggleq'oint. According to the present invention this pressure slide is wedge-shaped and may he inserted in different positions in its bearing guide. The pressure slide acts, by means of a bearing surface inclined to the direction of its movement, upon the locking lever witha lever arm the length of which is altered on shifting, i. e. on turning the pressure piece around its axis of movement about an angle of 180 for instance. Hereby the momentum of the force of the closing spring acting upon lengths of the toggle-joint is also altered, so that according to the insertion of the pressure piece the opened breech is closed'slower or quicker by the said spring as well as a greater or less resistance against opening is offered to the closed breech, whereby a difierent firing speed isobtained.

Preferably the point of attack of the toggle-joint locking lever upon the inclined surface of the pressure piece of the closing spring is arranged eccentrically to the pivot axis of the pressure slide, so that besides altering of the effective lever arm simultaneously the tension of the closing spring is altered also.

In the accompanying drawing one embodiment of the invention is shown by way of example in connection with a togglejoint breech.

Fig. 1 shows the toggle-joint in the stretched position on adjustment of the pressure piece of the closing spring for single firing as well as for slow permanent firing, the position the toggle-joint occupies, when the breech is opened, is shown in dash and dotted lines in this figure, and Fig. 2 illustrates the several parts of the toggle-joint in the stretched position after the pressure piece of the closing sprin has been turned to effect quick permanent ring, the position the toggle-joint occupies, when the breech is opened, also being shown in this figure by dash and dotted lines.

The breech consists in well known manner of the breech piece a, the toggle levers b b and the breech spring 0. The breech spring 0 bears, bymeans of a pressure piece 0 movably guided in thecasing of the spring, against a nose b fof therear toggle lever 6 which may be oscillated about the'pivot 6 arranged in the casingof the arm. Hereby the spring 0 forces the toggle-joint into the stretched position, so that the breech piece a comes into the locked position. The pressure piece 0 is, for instance, guided by noses 0 which slide in guide notches c of the spring casing and is thereby safely held against rotation. The front surface of the pressure piece 0 is bevelled. If the pressure piece 0 is inserted in its bearing guide in the position shown in Fig. 1, the closing springat opened breech acts with the component of its maximum force and with a relatively short lever arm in to close the breech, and reversely the closing spring opposes with a longer lever arm k a torque to .the opening of the closed breech. Both actions together cause slow breech movements during firing and therefore a low' firing speed.

If, however, the pressure piece is adjusted by turning it around its axis of displacement about an angle of 180, the closing. spring will, as the nose 6 of the locking lever-acts eccentrically to the shifting axis of the pressure piece upon the now turned inclined surface 0 at first be more tensioned, component P of the higher maximum force of the closing spring will act with a great lever arm 72. i. e. with a great torque, to close the breech, whereas a small momentum, acting with the very small lever arm k isto be overcome to open the closed breech. In this case the breech movements at firing are effected substantially quicker than under the conditions according to Figure .1. Experiments made with the constructionwhereupon at opened breech the,

shown have proved an increase of the firing speed of about 40%. What I claim is:

1. In an automatic fire arm, a toggle-joint V breech, a locking lever, a wedge shaped,

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pressure piece, capable of being inserted in different positions in a bearing guide, and

a closing spring acting by means of said pressure piece upon said locking lever, so that by turning of said pressure piece the lever arm of the said closing spring, acting upon said locking lever, and therefore the firing speed will be altered.

2. In an automatic fire arm, .a togglejoint breech, a locking lever, a Wedge shaped pressure piece, capable of being inserted in different positions in a bearing guide, and a closing spring acting by means of said pressure piece upon said locking lever, said pressure piece having an inclined surface and said locking lever Working against said surface outside the pivot axis of said pressure piece, so that by the turning of said pressure piece an alteration of the effective lever arm and simultaneously an alteration of the tension of the closing spring are eifected.

In testimony whereof I have affixed my signature.

KARL HEINEMANN. 

